WASHINGTON (CNN) -- After tapes of inflammatory statements made by Sen. Barack Obama's pastor came out last weekend, it appears to have had some negative impact on the Illinois senator.

Sen. Barack Obama and his church's former pastor, the Rev. Jeremiah Wright, in a 2005 photograph.

Nationally, Obama's lead over Sen. Hillary Clinton narrowed in a poll of polls -- which included CBS News, USA Today and Gallup.

The polls, taken between March 14-18, show Obama with 49 percent to Clinton's 43 percent.

"I don't think there is any doubt that the [Rev.] Jeremiah Wright controversy played a role in the 10-point drop in his favorable ratings," said pollster Terry Madonna. Watch reaction to Wright's comments »

Some of Wright's old sermons came under fire after a news report last week turned some of his most controversial comments into a YouTube phenomenon.

In one, the minister said America had brought the September 11 attacks upon itself. In another, he said Clinton had an advantage over Obama because she is white.